Plastics supplier RPC expects its adjusted pre-tax profits for the first half to be ahead of expectations after benefitting from synergies from the integration of its plastics and cardboard packaging business Superfos and growth in sales of products with big margins, such as coffee capsules.Revenues have been driven higher by the inclusion of results from Superfos, but the company also saw higher like-for-like turnover."The sales mix has substantially improved as a result of continuing growth in higher added value products such as pharmaceutical, long shelf life, personal care and coffee capsules," the company said.Synergies from the Superfos integration - which are now expected to reach £7m for the full year, higher than the previous estimate of £5m - as well an improvement in profitability at existing businesses, will help drive operating profit higher."This is driven by the better sales mix, efficient cost base and a less adverse impact from the time lag in passing through polymer prices to customers as polymer prices show a declining trend since the end of May. The adjusted profit after tax is expected to be ahead of management expectations."Chief executive Ron Marsh said: "The improvement in the first half year performance is encouraging and ahead of our expectations, despite the uncertainties surrounding the general economic environment. Based on our innovation capabilities, strong market positions and lean cost and capital base, I believe the group is well positioned to continue to deliver the performance necessary to achieve its stated aim of 20% ROCE (return on capital employed) by March 2014."---RG